Vascular access procedures and their subsequent complications represent a major cause of morbidity, hospitalization and cost for chronic hemodialysis patients. Over 20% of hospitalizations in hemodialysis patients in the United States are access-related, and the annual cost of access morbidity has been estimated at close to $1 billion. A-V fistulas have a lower incidence of stenosis, thrombosis, and infection than grafts, and increased longevity, but a large proportion of new fistulas never mature adequately to be usable for dialysis. A-V grafts are prone to frequent stenosis and thrombosis, requiring multiple radiologic and surgical interventions to maintain their long-term patency. Dialysis catheters are plagued with low blood flows and frequent thrombosis that impair the adequacy of dialysis, as well as frequent infections that result in bacteremia and life-threatening systemic complications. During the past few years the applicant has developed a multidisciplinary approach to vascular access at his institution, including a prospective, computerized database of all access procedures. In the context of this collaborative effort, the applicant has developed novel approaches to vascular access that have improved the standard of care and overall clinical outcomes related to vascular access. The goal of this grant is to optimize the applicant?s ability to pursue investigations regarding novel approaches aimed at improving vascular access outcomes in dialysis patients. Some of the specific questions that will be addressed include: (1) How can we increase the proportion of new A-V fistulas that mature adequately to be usable for dialysis? (2) How can we decrease the frequency of stenosis and thrombosis of A-V grafts? (3) How can we improve the blood flows and decrease the frequency of thrombosis of dialysis catheters? (4) How can we improve the clinical management of dialysis catheter-associated bacteremia? (5) How can we prevent the occurrence of dialysis catheter-associated infections? In the process of performing this clinical research, the candidate will also mentor Nephrology Fellows in the conduct of patient-oriented clinical research. The applicant will assist the trainees in acquiring the conceptual skills, research experience, and motivation required to pursue a successful career in Academic Nephrology.